Adjustable variable reciprocating stroke for a power system



June 16, 1964 D. s. STORDAHL v 3, 7,

ADJUSTABLE VARIABLE RECIPROCATING STROKE FOR A POWER SYSTEM Filed April 26, 1963 2 Sheets-Sheet 1 INVENTOR. 00mm 5. 5702mm ATTO EY June 16, 1964 D. sv STORDAHL 3,137,139

ADJUSTABLE VARIABLE RECIPROCATING STROKE FOR A POWER SYSTEM Filed April 26, 1965 2 Sheets-Sheet 2 INVENTOR. .Do/vAw 5. 570204/11 JAM/25 ATTORNEY United States Patent 3,137,139 Patented June 16, 1964 3,137,139 ADJUSTABLE VARIABLE RECIPROCATING STROKE FOR A POWER SYSTEM Donald S. Stordahl, 401 S. Phillips Ave.,

Sioux Falls, S. Dak. Filed Apr. 26, 1963, Ser. No.,275,961 4 Claims. (Cl. 60 52) This invention relates to a control means to give a power system an adjustable variable reciprocating stroke. The same was designed to allow material to be fed to a conveyor or other machine at a uniform and adjusted rate.

anism in one position, the same being shown in section.

FIG. 3 is a showing of the control mechanism of FIG. 1, the same being shown in an advanced position over FIG. 2.

As will be seen in FIG. 1 of the drawings, the double acting pump P comprises a cylinder 2 having therein pistons 3 and 4. The power to operate the pump P being shown here has an electric motor 5, although other forms of power could be used.

The pistons 3 and 4 in the pump cylinder 2 are connected to the operating shaft 6 of the electric motor 5.

Hydraulic fluid to operate the device is delivered to the pump P from a reservoir R under slight pressure. Fluid from the reservoir R enters the ends of the pump cylinder 2 through the check valves 7 and 8 by the line 9 and the branch lines 10 and 11 thereof.

Mounted on the same ends of the cylinder 2 as the check valves 7 and 8, are the check valves 12 and 13 which distribute the compressed fluid to pipe lines 14 and 24.

The pipe lines 14 and 24 convey the compressed fluid to the by-pass valves 16 and 17. The by-pass valves 16 and 17 distribute fluid to different ends of the work cylinder 18, said cylinder having therein the actuating piston 19. The actuating piston 19 has attached thereto a shaft 20, which shaft produces the desired reciprocating motion, according to the timing and direction thereof of the fluid in the different ends of the cylinder 18. The left end of the shaft 20 which projects through the cylinder 18 is used at the work end of the shaft.

The other end of the shaft 20 had an end projecting through the end of the cylinder 18 and this end of the shaft 20 controls the operating position of the by-pass valves 16 and 17.

Now'referring to FIGS. 2 and 3, which are enlarged figures of the control valves for causing the variable reciprocating stroke to the piston 19 and the operating shaft 20 attached thereto, it will be seen that the by-pass valves 16 and 17 have respectively projections 22 and 23 thereon, which are the operating devices for the valves to be moved by contact by the end 21 of the operating shaft 20.

The operating devices 22 and 23 for the by-pass valves 16 and 17 have their ends normally projected into the path of the end 21 of the operating shaft 20 and are held there by springs 22 and 23 Fluid from the reservoir R under slight pressure is fed through the line 9 and branch lines It and 11 to different ends of the pump cylinder 2 through check valves 7 and 8 as the motor 5 reciprocates the pistons 3 and 4 within the pump cylinder 2.

On the compression stroke of pistons 3 and 4, fluid is distributed through the check valves Hand 13 through lines 14 and 2.4 to the by-pass valve 16 and the stroke by-pass valve 17. The adjustability of the reciprocation of the operating shaft 20 is determined by the position of the by-pass valve 17 in relation to the end 21 of the operating shaft 20.

The by-pass valve 17 is adjustable to and from the cylinder 18 on a line in the path of the end of the operating shaft 20 and therefore has connected thereto the flexible pipe lines 24, 25 and 26 to accommodate this movement of position.

Connected to the by-pass valve 17 are the pipe lines 24 and 26, the line 24 leading compressed fluid from one end of the pump cylinder 2 through the check valve 13, the line 2 6 leading from the cut-off check valve 27, while the line 25 leads to the line 15 which in turn is connected to the line 30, being the return line to the reservoir R.

As the position of the by-pass valve 17 which controls the stroke is determined by its postiion in relation to the end 21 of the operating shaft 20, this control valve position is regulated by the screw rod 28 on which said valve 17 is mounted.

Means for controlling the position of the by-pass valve 17 are shown in the drawings as being a manual control member 29 attached to the outer end of the screw rod 28. However, this member 29 could be remotely controlled.

Between the by-pass valve 16 and the end of the cylinder 18 is interposed a cut-off and check valve 31. From this cut-off and check valve 31 is a line 32, which line 32 with the line 33 connected by the by-pass valve 16 empties into the line 30 which in turn is connected to the reservoir R.

On viewing FIGS. 1 and 2, it will be seen that the piston 3 has discharged fluid through the check valve 12 and through line 14 to the by-pass valve 16 where the fluid is entrained through the pipe line 33 to the line 30 and back to the reservoir R, this being surplus fluid not used to fill one end of the work cylinder 18.

In the meantime fluid under slight pressure flows from the reservoir R through the lines 9 and 11 and through the check valve 8 to fill the left side of the cylinder 2. On full stroke of the piston 4, fluid flows through the check valve 13, flexible line'24 to the by-pass valve 17 and therethrough by the flexible pipe line 26 to the cut-off check valve 27 and from there into the left end of the cylinder 18 to move the piston 19 to the right. In moving the piston 19 to the right, as shown in FIGS. 1 and 2, the end of the operating shaft 20 will contact and move the operator 22 of the by-pass valve 16 to the position shown in FIG. 3. The fluid contained within the cylinder 18 is allowed to escape through the lines 32 and 30 back to the reservoir R.

On further movement of the operating shaft 20 to the right, as shown in FIG. 3, the operator 23 of the by-pass valve 17 will be moved so that the excess fluid pressure built up in the line 24 can be by-passed through lines 25, 15 and 30 back to the reservoir R.

The length of the stroke of the mechanism, i.e., the movement of the operating shaft 20, will be governed by the position of the movable by-pass valve 17, that is to say, by moving the same to the right in relation to the cylinder 18, the length of the stroke will be lengthened whereas to move said by-pass valve 17 to the left the stroke of the operating shaft 20 willbe shortened.

Having thus described the embodiment of the invention with a view of clearly and concisely illustrating the same, I claim:

1. In a fluid system the combination of a reservoir having fluid therein, pipe lines leading from said reservoir to both' ends of a first cylinder, reciprocating pistons mounted in said cylinder, said pistons being connected to a drive shaft of a motor thereby forming a pump, check valves in the respective ends of said first cylinder leading to by 2. The structure according to claim 1, in which the bypass valves are spring biased in the path of the operating shaft.

3. The structure according to claim 1, in which at least one of the by-pass valves is mounted on a member hav- 7 ing a screw thread engagement with the by-pass valve;

4. The structure according to claim 1, in which the position of one of the by-pass valves is controlled by its position on a timing shaft supporting the valve.

References Cited in the file of-this patent HUNITED STATES PATENTS 1,418,616 Boisset June 6, 1922 1,714,545 Burns May 28, 1929 2,561,786 Davis July 24, 1951 OTHER REFERENCES German printed application, 1,073,888, printed J an. 21, 1960. I 

1. IN A FLUID SYSTEM THE COMBINATION OF A RESERVOIR HAVING FLUID THEREIN, PIPE LINES LEADING FROM SAID RESERVOIR TO BOTH ENDS OF A FIRST CYLINDER, RECIPROCATING PISTONS MOUNTED IN SAID CYLINDER, SAID PISTONS BEING CONNECTED TO A DRIVE SHAFT OF A MOTOR THEREBY FORMING A PUMP, CHECK VALVES IN THE RESPECTIVE ENDS OF SAID FIRST CYLINDER LEADING TO BYPASS VALVES THROUGH OTHER PIPE LINES, A SECOND OR WORK CYLINDER HAVING A PISTON THEREIN CONNECTED TO AN OPERATING SHAFT, SAID SHAFT EXTENDING THROUGH BOTH ENDS OF SAID WORK CYLINDER, PIPE LINES LEADING FROM SAID BY-PASS VALVES TO DIFFERENT ENDS OF SAID WORK CYLINDER, ONE OF SAID BY-PASS VALVES BEING POSITIONED ADJACENT ONE END OF SAID WORK CYLINDER AND IN LINE WITH AN END OF THE OPERATING SHAFT, SAID BY-PASS VALVES CONTROLLING THE TIMING OF SAID OPERATING SHAFT. 